In a principal aspect the present invention relates to a fan clutch wrench set, and more particularly to a set of wrenches which are useful for the removal of a fan clutch, associated with the fan of an internal combustion engine, by engaging the nut that retains the fan clutch on its shaft and releasing the nut from the shaft.
Typically, the internal combustion engine of a vehicle includes a fan which facilitates movement of air over the engine and through the engine radiator. The fan may not be operative at all times when the engine is running; for example, when cold during initial start up. Also, certain engines are designed so that the fan will remain operative even though the engine operation has terminated. Such internal combustion engines utilize a fan assembly driven by and connected with a fan drive shaft through a clutch mechanism. Often, this clutch mechanism operates in response to the speed of the engine and/or the temperature of the coolant or engine relative to ambient temperature. In other words, a clutch assembly typically interfaces between the fan and a drive shaft associated with the fan.
The fan is most often positioned at the forward end of a vehicle engine immediately adjacent a radiator, i.e. between a radiator and the engine block. Typically, the space between the fan and the engine or radiator is exceedingly limited. Thus, when attempting to replace the clutch assembly or otherwise repair the fan, it is extremely difficult to engage the nut which retains the fan clutch assembly and loosen that nut so as to permit replacement of the clutch. Consequently, there has developed a need to devise a fan clutch wrench set which enables an auto mechanic to access the clutch retention nut even though space is very limited.
Heretofore, wrenches made from flat plate material have been utilized or suggested for use in removal of a fan clutch retaining nut. Such wrenches usually require a very long lever arm in order to obtain an appropriate mechanical advantage to effect removal of the fan clutch retention nut. Often, within the engine compartment, however, there is limited room for such a wrench. Additionally, each engine size and brand typically has its own unique fan clutch wrench nut construction. That is, the size and/or shape of the retention nut may vary. Thus, there is a need to have either a rather large set of long handled flat plate wrenches, or to have some type of wrench that may be easily adjusted to accommodate various retention nut sizes. Consequently, there is a need for an improved fan clutch wrench set or construction.
Briefly, the present invention comprises a fan clutch wrench set which includes two basic component parts, a nut driving wrench and a drive handle. The nut driving wrench part of the set may be easily substituted to accommodate a fan clutch wrench retention nut of any size or shape. The nut driving wrench part or element of the set is relatively short (5 inches to 10 inches) in length and is formed from a flat metal plate. The nut driving wrench part includes a jaw at one end which fits over a fan clutch retention nut. At the opposite end, the nut driving wrench is configured with an arcuate driving surface which may be located in the plate or along one of the edges or sides of the flat plate forming the nut driving wrench part of the set.
The second element or part of the wrench set, namely the drive handle, is designed to engage against the arcuate driving surface of the nut driving wrench element. The drive handle preferably includes a yoke comprised of bifurcated arms which fit over the sides of the plate comprising the nut driving wrench so that the handle fits against the arcuate surface thereof and is held in that position. Thus, the drive handle is aligned against the drive surface of the driving wrench and a pneumatic tool or other driving device may be impacted against the drive handle to drive the nut driving wrench and thus rotate a fan clutch retention nut.
In one embodiment, a pin connecting the bifurcated arms helps retain the yoke in position by engaging a slot in the end of the nut driving wrench. Multiple nut driving wrenches may be provided in the set, each nut driving wrench having a separate jaw configuration and/or size to thereby accommodate various sized nuts associated with various fan clutch assemblies. Each of the driving wrenches, however, includes a jaw, a lever arm extending from the jaw and an opposite driving end which includes a driving surface that can be engaged by the separate drive handle. In each instance, the driving end of each nut driving wrench which is to be engaged by the drive handle has a substantially identical arcuate configuration and, preferably, a slot for receiving the pin provided in the drive handle yoke which fits over the sides of the nut driving wrench. Alternatively, the drive pin of the drive handle may engage an opening in the driving end of the nut driving wrench to drive the nut driving wrench.
Preferably The arcuate driving surface of the driving wrench and the driving surface of the handle have substantially the same arcuate shape. This facilitates application of uniform force by the handle on the driving wrench.
Thus, it is an object of the invention to provide an improved fan clutch wrench set capable of being utilized in restricted spaces found in an internal combustion engine compartment.
It is a further object of the invention to provide a highly efficient and reasonably priced fan clutch wrench set which is rugged and easy to manipulate and use, especially in restricted spaces.
Further, it is an object of the invention to provide a fan clutch wrench set which may be used in combination with a pneumatic driver or other driving mechanism to detach or unscrew a fan clutch wrench retention nut quickly and easily.
These and other objects, advantages and features of the invention will be set forth in the detailed description which follows.